A small crystal of AOP-RANTES (0.1 X 0.05 X 0.05 mm3) was rapidly cooled in the nitrogen stream and diffracted to 1.6 A resolution in 30 sec exposures. 159 frames of 1 degree oscillation were collected at 0.98 A wavelength. This resulted in a complete data set of excellent quality from 20 to 1.6 A resolution, with 99.8% overall completeness, I/sigma(I) of 31.8, and 11-fold redundancy. The structure was solved by molecular replacement, using the structure of Met-RANTES as a search model, and has been refined with the final R-factor of 16.7%, and a final R-free of 24.1%.